Scabiosa atropurpurea_Neal Kramer
Photo by Neal Kramer

Scabiosa atropurpurea Risk Assessment

Common names: pincushion flower

Scabiosa atropurpurea -- California

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Evaluation Summary
Summary: 
General Evaluation Information
Date of Evaluation: 
October 3, 2016
Evaluation Time (hrs): 
3 Hours
Evaluation Status: 
Completed
Plant Information
Plant Material: 
If the plant is a cultivar, and if the cultivar's behavior differs from its parent's (behavior), explain how: 
Regional Information
Region Name: 
Climate Matching Map
These maps were built using a toolkit created in collaboration between GreenInfo Network, PlantRight, Cal-IPC, and Agricultural Sustainability Institute at UC Davis.
Climate Matching Maps PDF: 
Invasive History and Climate Matching
1. Has the species (or cultivar or variety, if applicable; applies to subsequent "species" questions) become naturalized where it is not native?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
S. atropurpurea is naturalized in California in 18 counties according to Calflora, and Oregon and Washington (USDA NRCS). It is also naturalized in Great Britain, Germany, Belgium (DAISIE) and South America, Australia and New Zealand (GBIF).
Reference(s): 
2. Is the species (or cultivar or variety) noted as being naturalized in the US or world in a similar climate?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
High
Answer / Justification: 
S. atropurpurea is naturalized in California in 18 counties according to Calflora, and Oregon and Washington (USDA NRCS). It is also naturalized in Great Britain, Germany, Belgium (DAISIE) and South America, Australia and New Zealand (GBIF). The climate of California matches the S. atropurpurea distribution in Washington and Oregon (USDA NRCS), and Australia (GBIF) based on the Cal-IPC climate map.
3. Is the species (or cultivar or variety) noted as being invasive in the U.S. or world?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
High
Answer / Justification: 
Invasive in South Australia: South East Pest Management Strategy identified it as an environmental weed, managed to reduce economic/environmental impacts. http://www.environment.sa.gov.au/files/sharedassets/south_east/plants_an... Competitive interaction/impacts to Critically Endangered spiny daisy (Acanthocladium dockeri) indicate its causing environmental damage. http://www.environment.sa.gov.au/files/sharedassets/northern_and_yorke/p... Classified invasive by the Adelaide and Monoutn Lofty Ranges Natural Resources Management Board in Australia. http://www.environment.sa.gov.au/files/sharedassets/adelaide_and_mt_loft... Invasive in Chile (offshore islands), Australia, New Zealand. http://www.hear.org/pier/species/scabiosa_atropurpurea.htm Invasive in Texas: http://www.texasinvasives.org/
Reference(s): 
4. Is the species (or cultivar or variety) noted as being invasive in the US or world in a similar climate?
Yes or No: 
Yes
Points: 
3
Confidence Level: 
High
Answer / Justification: 
Invasive in South Australia, New Zealand and Chile on offshore islands which have some climate overlap with California. Invasive in South Australia: South East Pest Management Strategy identified it as an environmental weed, managed to reduce economic/environmental impacts. http://www.environment.sa.gov.au/files/sharedassets/south_east/plants_an... Competitive interaction/impacts to Critically Endangered spiny daisy (Acanthocladium dockeri) indicate its causing environmental damage. http://www.environment.sa.gov.au/files/sharedassets/northern_and_yorke/p... Classified invasive by the Adelaide and Monoutn Lofty Ranges Natural Resources Management Board in South Australia. http://www.environment.sa.gov.au/files/sharedassets/adelaide_and_mt_loft... Listed as invasive in Chile (offshore islands) and New Zealand: www.hear.org/pier/species/scabiosa_atropurpurea.htm Additional information on close relative: Field scabious (Knautia arvensis) is in a genus closely related to Scabiosa, and is considered a noxious weed in British Columbia under the BC Weed Control Act, competing with forage and pasture land. It is also listed invasive in Alberta and Saskatchewan provinces. It is found in the portion of BC that is a climate match with California, using the Cal-IPC climate map. http://bcinvasives.ca/invasive-species/identify/invasive-species/invasiv...
Reference(s): 
5. Are other species of the same genus (or closely related genera) invasive in a similar climate?
Yes or No: 
No
Points: 
0
Confidence Level: 
High
Answer / Justification: 
All the Scabiosa species listed in Randall (2012) are not classified as Invasive. The only Scabiosa species with Environmental Weed listed is S. atropurpurea.
Reference(s): 
6. Is the species (or cultivar or variety) found predominately in a climate matching the region of concern?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
Medium
Answer / Justification: 
The climate of California matches the S. atropurpurea distribution in most of its range (GBIF). Some areas which do not match are in Australia, New Zealand and northern Europe.
Impact on Native Plants and Animals
7. Does this plant displace native plants and dominate (overtop or smother) the plant community in areas where it has established?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Low
Answer / Justification: 
In Texas the species is noted to form monocultures (http://www.texasinvasives.org/plant_database/detail.php?symbol=SCAT).
Reference(s): 
8. Is the plant noted as promoting fire and/or changing fire regimes?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
There is no evidence that S. atropurpurea promotes or changes fire regimes.
Reference(s): 
9. Is the plant a health risk to humans or animals/fish? Has the species been noted as impacting grazing systems?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
There is no evidence that S. atropurpurea is a health risk or impacts grazing systems.
Reference(s): 
10. Does the plant produce impenetrable thickets, blocking or slowing movement of animals, livestock, or humans?
Yes or No: 
No
Points: 
0
Confidence Level: 
High
Answer / Justification: 
S. atropurpurea is a soft annual plant with a low-growing rosette and pedicels of single flowers. It grows to 60 cm or less so would not block movement of humans or animals.
Reference(s): 
Reproductive Strategies
11. Does this species (or cultivar or variety) reproduce and spread vegetatively?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
There is no information on whether S. atropurpurea spreads vegetatively. Since it is an annual this is not likely.
Reference(s): 
12. If naturally detached fragments from this plant are capable of producing new plants, is this a common method of reproduction for the plant?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
There is no information on whether S. atropurpurea spreads vegetatively. Since it is an annual this is not likely.
Reference(s): 
13. Does the species (or cultivar or variety) commonly produce viable seed?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
Annual or short-lived perennial which propagates by seed.
Reference(s): 
14. Does this plant produce copious viable seeds each year (> 1000)?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Medium
Answer / Justification: 
A single plant of a close relative, S. arvensis, can produce up to 2,000 seeds http://bcinvasives.ca/invasive-species/identify/invasive-species/invasive-plants/field-scabious/. Note from Eric Wrubel: The close relative referred to here, Knautia arvensis, is invasive in BC. Scabiosa atropurpurea can be expected to produce a similar, or greater number of seeds. I estimate each flower head produces 50-100 seeds, and mature plants can produce up to 100 flowerheads, yielding up to 1,000 seeds.
Reference(s): 
15. Is there significant germination (>25%) of seeds the next growing season, with no requirement of an infrequent environmental condition for seeds to germinate (i.e. fire) or long dormancy period?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Medium
Answer / Justification: 
The Kew seed database states that seed germination is 80%. The germination of seed is 35-40% after 15 years of storage (http://data.kew.org/sid/SidServlet?ID=20566&Num=2jd).
Reference(s): 
16. Does this plant produce viable seed within the first three years (for an herbaceous species) to five years (for a woody species) after germination?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
Since S. atropurpurea is an annual it produces seed every year and is often noted as re-seeding naturally in gardens.
Reference(s): 
17. Does this plant continuously produce seed for >3 months each year or does seed production occur more than once a year?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Medium
Answer / Justification: 
S. atropurpurea flowers from March to November so would be producing seed for greater than 3 months.
Reference(s): 
Dispersal
18. Are the plant’s propagules frequently dispersed long distance (>100 m) by mammals or birds or via domestic animals?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Low
Answer / Justification: 
On the Kew seed information database it is noted that dispersal is by animals (http://data.kew.org/sid/SidServlet?ID=20566&Num=2jd).
Reference(s): 
19. Are the plant’s propagules frequently dispersed long distance (>100 m) by wind or water?
Yes or No: 
No
Points: 
0
Confidence Level: 
Low
Answer / Justification: 
There is no evidence that propagules are dispersed by wind or water. The diaspores are connected to the seed heads so that propagules are not light and adapted for wind or water dispersal.
Reference(s): 
20. Are the plant’s propagules frequently dispersed via contaminated seed (agriculture or wildflower packets), equipment, vehicles, boats or clothing/shoes?
Yes or No: 
No
Points: 
0
Confidence Level: 
Low
Answer / Justification: 
There is not evidence that propagules are dispersed by contaminated seed, equipment, vehicles, boats or clothing.
Reference(s): 
Evaluation Notes
Total PRE Score

  • < 13 : accept (low risk of invasiveness)
  • 13 - 15 : evaluate further
  • > 15 : reject (high risk of invasiveness)

PRE Score: 
17
Number of questions answered: 
20
Screener Confidence (%): 
65.0
PRE Content Access and Privacy
Evaluation visibility: 
Public - accessible to all site users

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